feat(resilience): add circuit breaker for downstream services

- New CircuitBreaker class: CLOSED → OPEN → HALF_OPEN three-state model
- Zero external dependencies, ~90 lines, fail-open semantics
- KnowledgeClientService: threshold=5, cooldown=60s, protects all 9 endpoints
- PaymentClientService: threshold=3, cooldown=30s, protects all 7 endpoints
- Both services refactored to use protectedFetch() — cleaner code, fewer try-catch
- Replaces verbose per-method error handling with centralized circuit breaker
- When tripped: returns null/empty fallback instantly, no network call

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/services/conversation-service/src/infrastructure/common/circuit-breaker.ts

@@ -0,0 +1,96 @@
+/**
+ * Circuit Breaker — 轻量级熔断器
+ *
+ * 三态模型：
+ *   CLOSED  → 正常放行请求
+ *   OPEN    → 熔断，直接返回 fallback（连续 failureThreshold 次失败触发）
+ *   HALF_OPEN → 探测恢复，允许 1 个请求通过检测下游是否恢复
+ *
+ * 零外部依赖，纯内存实现，适合单实例服务（多实例需用 Redis 版本）
+ */
+
+import { Logger } from '@nestjs/common';
+
+export type CircuitState = 'CLOSED' | 'OPEN' | 'HALF_OPEN';
+
+export interface CircuitBreakerOptions {
+  /** 服务名称（用于日志） */
+  name: string;
+  /** 连续失败触发熔断的阈值 */
+  failureThreshold: number;
+  /** 熔断持续时间（ms），过后进入 HALF_OPEN */
+  resetTimeoutMs: number;
+}
+
+export class CircuitBreaker {
+  private readonly logger: Logger;
+  private state: CircuitState = 'CLOSED';
+  private failureCount = 0;
+  private lastFailureTime = 0;
+  private readonly name: string;
+  private readonly failureThreshold: number;
+  private readonly resetTimeoutMs: number;
+
+  constructor(options: CircuitBreakerOptions) {
+    this.name = options.name;
+    this.failureThreshold = options.failureThreshold;
+    this.resetTimeoutMs = options.resetTimeoutMs;
+    this.logger = new Logger(`CircuitBreaker:${this.name}`);
+  }
+
+  /**
+   * 执行受保护的操作
+   * @param fn 要执行的异步操作
+   * @param fallback 熔断时的降级返回值
+   */
+  async execute<T>(fn: () => Promise<T>, fallback: T): Promise<T> {
+    // OPEN 状态：检查是否可以转为 HALF_OPEN
+    if (this.state === 'OPEN') {
+      const elapsed = Date.now() - this.lastFailureTime;
+      if (elapsed >= this.resetTimeoutMs) {
+        this.state = 'HALF_OPEN';
+        this.logger.log(`${this.name}: OPEN → HALF_OPEN (${elapsed}ms elapsed, probing...)`);
+      } else {
+        // 仍在熔断窗口内，直接返回 fallback
+        return fallback;
+      }
+    }
+
+    try {
+      const result = await fn();
+
+      // 成功：重置计数器
+      if (this.state === 'HALF_OPEN') {
+        this.logger.log(`${this.name}: HALF_OPEN → CLOSED (probe succeeded)`);
+      }
+      this.state = 'CLOSED';
+      this.failureCount = 0;
+      return result;
+    } catch (error) {
+      this.failureCount++;
+      this.lastFailureTime = Date.now();
+
+      if (this.failureCount >= this.failureThreshold) {
+        this.state = 'OPEN';
+        this.logger.warn(
+          `${this.name}: → OPEN (${this.failureCount} consecutive failures, cooldown ${this.resetTimeoutMs}ms)`,
+        );
+      }
+
+      this.logger.debug(
+        `${this.name}: failure ${this.failureCount}/${this.failureThreshold} — ${error}`,
+      );
+      return fallback;
+    }
+  }
+
+  /** 当前状态 */
+  getState(): CircuitState {
+    return this.state;
+  }
+
+  /** 连续失败次数 */
+  getFailureCount(): number {
+    return this.failureCount;
+  }
+}

packages/services/conversation-service/src/infrastructure/knowledge/knowledge-client.service.ts

@@ -1,5 +1,6 @@
-import { Injectable, OnModuleInit } from '@nestjs/common';
+import { Injectable, OnModuleInit, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
+import { CircuitBreaker } from '../common/circuit-breaker';
 
 /**
  * RAG 检索结果
@@ -63,13 +64,36 @@ interface ApiResponse<T> {
  */
 @Injectable()
 export class KnowledgeClientService implements OnModuleInit {
+  private readonly logger = new Logger(KnowledgeClientService.name);
   private baseUrl: string;
+  private readonly circuitBreaker: CircuitBreaker;
 
-  constructor(private configService: ConfigService) {}
+  constructor(private configService: ConfigService) {
+    this.circuitBreaker = new CircuitBreaker({
+      name: 'knowledge-service',
+      failureThreshold: 5,
+      resetTimeoutMs: 60_000,
+    });
+  }
 
   onModuleInit() {
     this.baseUrl = this.configService.get<string>('KNOWLEDGE_SERVICE_URL') || 'http://knowledge-service:3003';
-    console.log(`[KnowledgeClient] Initialized with base URL: ${this.baseUrl}`);
+    this.logger.log(`Initialized with base URL: ${this.baseUrl}`);
+  }
+
+  /**
+   * 受熔断器保护的 fetch — 连续 5 次失败后熔断 60s
+   * 熔断期间直接返回 null，不发起网络请求
+   */
+  private protectedFetch(url: string, init?: RequestInit): Promise<Response | null> {
+    return this.circuitBreaker.execute(
+      async () => {
+        const resp = await fetch(url, init);
+        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
+        return resp;
+      },
+      null,
+    );
   }
 
   /**
@@ -82,24 +106,14 @@ export class KnowledgeClientService implements OnModuleInit {
     includeMemories?: boolean;
     includeExperiences?: boolean;
   }): Promise<RAGResult | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/knowledge/retrieve`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/knowledge/retrieve`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<RAGResult>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        console.error(`[KnowledgeClient] RAG retrieve failed: ${response.status}`);
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<RAGResult>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[KnowledgeClient] RAG retrieve error:', error);
-      return null;
-    }
   }
 
   /**
@@ -110,48 +124,28 @@ export class KnowledgeClientService implements OnModuleInit {
     userId?: string;
     category?: string;
   }): Promise<string | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/knowledge/retrieve/prompt`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/knowledge/retrieve/prompt`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<{ context: string }>;
-      if (!response.ok) {
+    return data.success ? data.data.context : null;
-        console.error(`[KnowledgeClient] RAG retrieve/prompt failed: ${response.status}`);
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<{ context: string }>;
-      return data.success ? data.data.context : null;
-    } catch (error) {
-      console.error('[KnowledgeClient] RAG retrieve/prompt error:', error);
-      return null;
-    }
   }
 
   /**
    * 检查是否离题
    */
   async checkOffTopic(query: string): Promise<OffTopicResult> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/knowledge/check-off-topic`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/knowledge/check-off-topic`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({ query }),
-        body: JSON.stringify({ query }),
+    });
-      });
+    if (!resp) return { isOffTopic: false, confidence: 0 };
-
+    const data = (await resp.json()) as ApiResponse<OffTopicResult>;
-      if (!response.ok) {
+    return data.success ? data.data : { isOffTopic: false, confidence: 0 };
-        console.error(`[KnowledgeClient] checkOffTopic failed: ${response.status}`);
-        return { isOffTopic: false, confidence: 0 };
-      }
-
-      const data = (await response.json()) as ApiResponse<OffTopicResult>;
-      return data.success ? data.data : { isOffTopic: false, confidence: 0 };
-    } catch (error) {
-      console.error('[KnowledgeClient] checkOffTopic error:', error);
-      return { isOffTopic: false, confidence: 0 };
-    }
   }
 
   /**
@@ -165,24 +159,14 @@ export class KnowledgeClientService implements OnModuleInit {
     sourceConversationId?: string;
     relatedCategory?: string;
   }): Promise<UserMemory | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/user`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/user`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<UserMemory>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        console.error(`[KnowledgeClient] saveUserMemory failed: ${response.status}`);
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<UserMemory>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[KnowledgeClient] saveUserMemory error:', error);
-      return null;
-    }
   }
 
   /**
@@ -193,44 +177,24 @@ export class KnowledgeClientService implements OnModuleInit {
     query: string;
     limit?: number;
   }): Promise<UserMemory[]> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/user/search`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/user/search`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return [];
-
+    const data = (await resp.json()) as ApiResponse<UserMemory[]>;
-      if (!response.ok) {
+    return data.success ? data.data : [];
-        console.error(`[KnowledgeClient] searchUserMemories failed: ${response.status}`);
-        return [];
-      }
-
-      const data = (await response.json()) as ApiResponse<UserMemory[]>;
-      return data.success ? data.data : [];
-    } catch (error) {
-      console.error('[KnowledgeClient] searchUserMemories error:', error);
-      return [];
-    }
   }
 
   /**
    * 获取用户最重要的记忆
    */
   async getUserTopMemories(userId: string, limit = 5): Promise<UserMemory[]> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/user/${userId}/top?limit=${limit}`);
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/user/${userId}/top?limit=${limit}`);
+    if (!resp) return [];
-
+    const data = (await resp.json()) as ApiResponse<UserMemory[]>;
-      if (!response.ok) {
+    return data.success ? data.data : [];
-        console.error(`[KnowledgeClient] getUserTopMemories failed: ${response.status}`);
-        return [];
-      }
-
-      const data = (await response.json()) as ApiResponse<UserMemory[]>;
-      return data.success ? data.data : [];
-    } catch (error) {
-      console.error('[KnowledgeClient] getUserTopMemories error:', error);
-      return [];
-    }
   }
 
   /**
@@ -243,48 +207,31 @@ export class KnowledgeClientService implements OnModuleInit {
     activeOnly?: boolean;
     limit?: number;
   }): Promise<SystemExperience[]> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/experience/search`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/experience/search`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return [];
-
+    const data = (await resp.json()) as ApiResponse<SystemExperience[]>;
-      if (!response.ok) {
+    return data.success ? data.data : [];
-        console.error(`[KnowledgeClient] searchExperiences failed: ${response.status}`);
-        return [];
-      }
-
-      const data = (await response.json()) as ApiResponse<SystemExperience[]>;
-      return data.success ? data.data : [];
-    } catch (error) {
-      console.error('[KnowledgeClient] searchExperiences error:', error);
-      return [];
-    }
   }
 
   /**
    * 初始化用户节点（Neo4j）
    */
   async initializeUser(userId: string): Promise<boolean> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/user`, {
-      // 通过保存一个初始记忆来初始化用户
+      method: 'POST',
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/user`, {
+      headers: { 'Content-Type': 'application/json' },
-        method: 'POST',
+      body: JSON.stringify({
-        headers: { 'Content-Type': 'application/json' },
+        userId,
-        body: JSON.stringify({
+        memoryType: 'FACT',
-          userId,
+        content: '用户首次访问系统',
-          memoryType: 'FACT',
+        importance: 10,
-          content: '用户首次访问系统',
+      }),
-          importance: 10,
+    });
-        }),
+    return resp !== null;
-      });
-
-      return response.ok;
-    } catch (error) {
-      console.error('[KnowledgeClient] initializeUser error:', error);
-      return false;
-    }
   }
 
   /**
@@ -299,24 +246,14 @@ export class KnowledgeClientService implements OnModuleInit {
     confidence?: number;
     relatedCategory?: string;
   }): Promise<SystemExperience | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/memory/experience`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/memory/experience`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify(params),
-        body: JSON.stringify(params),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<SystemExperience>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        console.error(`[KnowledgeClient] saveExperience failed: ${response.status}`);
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<SystemExperience>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[KnowledgeClient] saveExperience error:', error);
-      return null;
-    }
   }
 
   // ============================================================

packages/services/conversation-service/src/infrastructure/payment/payment-client.service.ts

@@ -1,5 +1,6 @@
-import { Injectable, OnModuleInit } from '@nestjs/common';
+import { Injectable, OnModuleInit, Logger } from '@nestjs/common';
 import { ConfigService } from '@nestjs/config';
+import { CircuitBreaker } from '../common/circuit-breaker';
 
 /**
  * 支付结果
@@ -50,16 +51,36 @@ interface ApiResponse<T> {
  */
 @Injectable()
 export class PaymentClientService implements OnModuleInit {
+  private readonly logger = new Logger(PaymentClientService.name);
   private baseUrl: string;
+  private readonly circuitBreaker: CircuitBreaker;
 
-  constructor(private configService: ConfigService) {}
+  constructor(private configService: ConfigService) {
+    this.circuitBreaker = new CircuitBreaker({
+      name: 'payment-service',
+      failureThreshold: 3,
+      resetTimeoutMs: 30_000,
+    });
+  }
 
   onModuleInit() {
     this.baseUrl =
       this.configService.get<string>('PAYMENT_SERVICE_URL') ||
       'http://payment-service:3002';
-    console.log(
+    this.logger.log(`Initialized with base URL: ${this.baseUrl}`);
-      `[PaymentClient] Initialized with base URL: ${this.baseUrl}`,
+  }
+
+  /**
+   * 受熔断器保护的 fetch — 连续 3 次失败后熔断 30s
+   */
+  private protectedFetch(url: string, init?: RequestInit): Promise<Response | null> {
+    return this.circuitBreaker.execute(
+      async () => {
+        const resp = await fetch(url, init);
+        if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
+        return resp;
+      },
+      null,
     );
   }
 
@@ -72,34 +93,21 @@ export class PaymentClientService implements OnModuleInit {
     serviceCategory?: string;
     conversationId?: string;
   }): Promise<OrderInfo | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/orders`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/orders`, {
+      method: 'POST',
-        method: 'POST',
+      headers: {
-        headers: {
+        'Content-Type': 'application/json',
-          'Content-Type': 'application/json',
+        'x-user-id': params.userId,
-          'x-user-id': params.userId,
+      },
-        },
+      body: JSON.stringify({
-        body: JSON.stringify({
+        serviceType: params.serviceType,
-          serviceType: params.serviceType,
+        serviceCategory: params.serviceCategory,
-          serviceCategory: params.serviceCategory,
+        conversationId: params.conversationId,
-          conversationId: params.conversationId,
+      }),
-        }),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<OrderInfo>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        const errText = await response.text();
-        console.error(
-          `[PaymentClient] createOrder failed: ${response.status} ${errText}`,
-        );
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<OrderInfo>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] createOrder error:', error);
-      return null;
-    }
   }
 
   /**
@@ -109,30 +117,17 @@ export class PaymentClientService implements OnModuleInit {
     orderId: string;
     method: string;
   }): Promise<PaymentResult | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/payments`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/payments`, {
+      method: 'POST',
-        method: 'POST',
+      headers: { 'Content-Type': 'application/json' },
-        headers: { 'Content-Type': 'application/json' },
+      body: JSON.stringify({
-        body: JSON.stringify({
+        orderId: params.orderId,
-          orderId: params.orderId,
+        method: params.method,
-          method: params.method,
+      }),
-        }),
+    });
-      });
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<PaymentResult>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        const errText = await response.text();
-        console.error(
-          `[PaymentClient] createPayment failed: ${response.status} ${errText}`,
-        );
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<PaymentResult>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] createPayment error:', error);
-      return null;
-    }
   }
 
   /**
@@ -141,27 +136,15 @@ export class PaymentClientService implements OnModuleInit {
   async checkPaymentStatus(
     paymentId: string,
   ): Promise<{ status: string; paidAt?: string } | null> {
-    try {
+    const resp = await this.protectedFetch(
-      const response = await fetch(
+      `${this.baseUrl}/api/v1/payments/${paymentId}/status`,
-        `${this.baseUrl}/api/v1/payments/${paymentId}/status`,
+    );
-      );
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<{
-      if (!response.ok) {
+      status: string;
-        console.error(
+      paidAt?: string;
-          `[PaymentClient] checkPaymentStatus failed: ${response.status}`,
+    }>;
-        );
+    return data.success ? data.data : null;
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<{
-        status: string;
-        paidAt?: string;
-      }>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] checkPaymentStatus error:', error);
-      return null;
-    }
   }
 
   /**
@@ -175,75 +158,39 @@ export class PaymentClientService implements OnModuleInit {
     paidAt?: string;
     completedAt?: string;
   } | null> {
-    try {
+    const resp = await this.protectedFetch(
-      const response = await fetch(
+      `${this.baseUrl}/api/v1/orders/${orderId}/status`,
-        `${this.baseUrl}/api/v1/orders/${orderId}/status`,
+    );
-      );
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<{
-      if (!response.ok) {
+      orderId: string;
-        console.error(
+      status: string;
-          `[PaymentClient] getOrderStatus failed: ${response.status}`,
+      paidAt?: string;
-        );
+      completedAt?: string;
-        return null;
+    }>;
-      }
+    return data.success ? data.data : null;
-
-      const data = (await response.json()) as ApiResponse<{
-        orderId: string;
-        status: string;
-        paidAt?: string;
-        completedAt?: string;
-      }>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] getOrderStatus error:', error);
-      return null;
-    }
   }
 
   /**
    * 查询用户订单列表
    */
   async getUserOrders(userId: string): Promise<OrderInfo[]> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/orders`, {
-      const response = await fetch(`${this.baseUrl}/api/v1/orders`, {
+      headers: { 'x-user-id': userId },
-        headers: { 'x-user-id': userId },
+    });
-      });
+    if (!resp) return [];
-
+    const data = (await resp.json()) as ApiResponse<OrderInfo[]>;
-      if (!response.ok) {
+    return data.success ? data.data : [];
-        console.error(
-          `[PaymentClient] getUserOrders failed: ${response.status}`,
-        );
-        return [];
-      }
-
-      const data = (await response.json()) as ApiResponse<OrderInfo[]>;
-      return data.success ? data.data : [];
-    } catch (error) {
-      console.error('[PaymentClient] getUserOrders error:', error);
-      return [];
-    }
   }
 
   /**
    * 获取单个订单详情
    */
   async getOrderDetail(orderId: string): Promise<OrderInfo | null> {
-    try {
+    const resp = await this.protectedFetch(`${this.baseUrl}/api/v1/orders/${orderId}`);
-      const response = await fetch(`${this.baseUrl}/api/v1/orders/${orderId}`);
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<OrderInfo>;
-      if (!response.ok) {
+    return data.success ? data.data : null;
-        console.error(
-          `[PaymentClient] getOrderDetail failed: ${response.status}`,
-        );
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<OrderInfo>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] getOrderDetail error:', error);
-      return null;
-    }
   }
 
   /**
@@ -252,28 +199,15 @@ export class PaymentClientService implements OnModuleInit {
   async cancelOrder(
     orderId: string,
   ): Promise<{ orderId: string; status: string } | null> {
-    try {
+    const resp = await this.protectedFetch(
-      const response = await fetch(
+      `${this.baseUrl}/api/v1/orders/${orderId}/cancel`,
-        `${this.baseUrl}/api/v1/orders/${orderId}/cancel`,
+      { method: 'POST' },
-        { method: 'POST' },
+    );
-      );
+    if (!resp) return null;
-
+    const data = (await resp.json()) as ApiResponse<{
-      if (!response.ok) {
+      orderId: string;
-        const errText = await response.text();
+      status: string;
-        console.error(
+    }>;
-          `[PaymentClient] cancelOrder failed: ${response.status} ${errText}`,
+    return data.success ? data.data : null;
-        );
-        return null;
-      }
-
-      const data = (await response.json()) as ApiResponse<{
-        orderId: string;
-        status: string;
-      }>;
-      return data.success ? data.data : null;
-    } catch (error) {
-      console.error('[PaymentClient] cancelOrder error:', error);
-      return null;
-    }
   }
 }